“We thank Puma for the cooperative relationship that, along with the responsiveness of the National
Medical Products Administration, allowed us to achieve NERLYNX market approval just 18 months after
submission, a testament to the CANbridge regulatory expertise,” said James Xue, PhD, Founder,
Chairman and CEO, CANbridge Pharmaceuticals Inc. “Women in China with early stage breast cancer
now have first-time access to oral adjuvant therapy.”

Alan H. Auerbach, Chief Executive Officer and President of Puma, added, “Reducing the risk of
recurrence in HER2-positive early stage breast cancer patients remains paramount for Puma and our
global partners. Marketing approval in the region represents an important milestone as we continue to
execute on our global commercial strategy. We thank and congratulate CANbridge for reaching this
important milestone.”

About HER2-Positive Breast Cancer

Approximately 20 to 25 percent of breast cancer tumors over-express the HER2 protein. HER2-positive
breast cancer is often more aggressive than other types of breast cancer, increasing the risk of disease
progression and death. Although research has shown that trastuzumab can reduce the risk of early stage
HER2-positive breast cancer returning after surgery, up to 25% of patients treated with trastuzumab
experience recurrence.

About Puma Biotechnology

Puma Biotechnology, Inc. is a biopharmaceutical company with a focus on the development and
commercialization of innovative products to enhance cancer care. Puma in-licenses the global development
and commercialization rights to PB272 (neratinib, oral), PB272 (neratinib, intravenous) and PB357.
Neratinib, oral was approved by the U.S. Food and Drug Administration in 2017 for the extended adjuvant
treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer, following adjuvant
trastuzumab-based therapy, and is marketed in the United States as NERLYNX® (neratinib) tablets. In
February 2020, NERLYNX was also approved by the FDA in combination with capecitabine for the
treatment of adult patients with advanced or metastatic HER2-positive breast cancer who have received two
or more prior anti-HER2-based regimens in the metastatic setting. NERLYNX was granted marketing
authorization by the European Commission in 2018 for the extended adjuvant treatment of adult patients with
early stage hormone receptor-positive HER2-overexpressed/amplified breast cancer and who are less than
one year from completion of prior adjuvant trastuzumab-based therapy. NERLYNX is a registered trademark
of Puma Biotechnology, Inc.

Further information about Puma Biotechnology may be found at www.pumabiotechnology.com.

IMPORTANT SAFETY INFORMATION

NERLYNX® (neratinib) tablets, for oral use
INDICATIONS AND USAGE: NERLYNX is a kinase inhibitor indicated:

As a single agent, for the extended adjuvant treatment of adult patients with early-stage HER2-positive breast cancer, to follow adjuvant trastuzumab-based therapy.

In combination with capecitabine, for the treatment of adult patients with advanced or metastatic HER2-positive breast cancer, who have received two or more prior anti-HER2 based regimens in the metastatic setting.

To help ensure patients have access to NERLYNX, Puma has implemented the Puma Patient Lynx support program to assist patients and healthcare providers with reimbursement support and referrals to resources that can help with financial assistance. More information on the Puma Patient Lynx program can be found at www.NERLYNX.com or 1-855-816-5421.

Forward-Looking Statements
This press release contains forward-looking statements, including statements regarding the worldwide expansion of NERLYNX. All forward-looking statements involve risks and uncertainties that could cause Puma’s actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions, and actual outcomes and results could differ materially from these statements due to a number of factors, which include, but are not limited to, any adverse impact on Puma’s business or the global economy and financial markets, generally, from the global COVID-19 pandemic, and the risk factors disclosed in the periodic and current reports filed by Puma with the Securities and Exchange Commission from time to time, including Puma’s Annual Report on Form 10-K for the year ended December 31, 2019, Puma’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, and subsequent reports. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. Puma assumes no obligation to update these forward-looking statements, except as required by law.